66 THE TWO ATMOSPHERES 



years ago. Endogenic processes, e.g. orogenetic cycles, on the other 

 hand, were essentially the same for the oldest rocks dated at the time 

 when this text was written; that is, 3.3 billion years ago. 



There is, consequently, a marked difference in the history of the 

 development of endogenic and exogenic processes. At a time when 

 the endogenic processes followed already an actualistic pattern, the 

 latter were still under the influence of the pre-actualistic atmosphere, 

 and completely different from the exogenic processes of younger 

 geologic history and of the present. 



